Electric time piece



Feb. 2, 1960 P. E. BIEMILLER 2,923,123

ELECTRIC TIME PIECE Filed May 31, 1957 2 Sheets-Sheet 1 FIG. I

INVENTOR PHILIP E. BIEMILLER ATTORNEY Feb. 2, 1960 P. E. BIEMILLER 2,923,123

ELECTRIC TIME PIECE Filed May 31, 1957 2 Sheets-Sheet 2 INVENTOR PHILIP E. BIEMILLER BY z ATTORNEY 2,923,123 ELECTRIC TIME PIECE ihilip 'Biemiller, Landisville, Pa., assignor' to Hamilton Watch Company, Lancaster, Pa., a corporation of Pennsylvania Application May 31,- 1957, Serial No. 662,850

Claims. (CI. 58-28) that the available electrical energy be converted into mechanical energy as efiiciently as possible so that an extended battery life can be obtained. The component parts of the electric wrist watch, including the battery, the oscillating frequency controlling element, the magnets maintaining the permanent magnetic field and the mechanical movement must be kept to a minimum size.

'In assignees copending application, Serial No. 578,843 filed April 17, 1956, there is disclosed an electric wrist watch utilizing cylindrical disk type magnets having length to diameter ratios of substantially no greater than one.

United States Patent ice it is another object of the invention to provide an electric watch containing a generally circular permanent magnet encircling the watch movement and simultaneously serving as a magnet and movement or case ring.

These and further objects and advantages of the invention will become more apparent upon reference in the following specification and claims and appended drawings wherein:

Figure 1 is a plan view of the train side of an electric Watch constructed according to the invention with the balance cock removed;

' Figure 2 is a vertical elevation of the watch;

Figure 3 is a plan view of the train side of an electric watch constructed according to another embodiment of the invention with the balance cock removed; and

Figure 4 is a vertical side elevation of the watch.

Referring to Figures 1 and 2, there is shown an electric wrist watch 10 comprising a pillar plate 12 which supports a disc-type battery 14 which is held in place by means of a spring 18. The spring 18 is mounted in a pair of posts 20 and 22. A balance staff 24 is supported between conventional hearings in the pillar plate In assignees copending application Serial No. 631,686,

filed December 31, 1956 there is disclosed another type of electric wrist watch utilizing a specially shaped battery in conjunction with a more or less semicircular permanent magnet.

Under certain circumstances, and with certain types of magnetic materials, it may be desirable to provide a permanent magnet having a length to diameter ratio which is materially greater than one. It has now been found that this may be satisfactorily accomplished by utilizing a permanent magnet which is essentially circular in shape and which substantially encircles the watch movement. While the semicircular magnet disclosed in the aforementioned copending application, Serial No. 631,686 is generally used with a centrally mounted balance wheel, it has been found that with a substantially circular permanent magnet of the type disclosed herein it is possible to use an eccentrically mounted balance wheel of the same type as that used in the watch disclosed in the aforementioned copending application Serial No. 578,843, which uses small disk-type magnets.

It is accordingly 9. primary object of the present invention to provide an electric watch having a generally circular permanent magnet and an eccentrically mounted frequency controlling element which also supplies the mechanical energy to the gear train.

It is another object of the invention to provide an electric watch having a permanent magnet having a high length to diameter ratio arranged in circular form about the watch movement.

It is another object of the invention to provide an electric watch containing a generally circular permanent magnet encircling the watch movement and having a pair of oppositely disposed pole pieces at one side of the watch movement cooperating with a frequency controlling element mounted eccentrically with respect to the center of the .watch movement. 7

q a controlling and limiting 12 and balance cock 26 and carries a balance wheel 28.

The balance wheel 28 comprises a rim 30 carried by cross bars 32 attached to a hub mounted on the balance staff 24. The rim 30 of the balance Wheel is broken away at 31 to receive a sector-shaped coil 34 which is I attached thereto by means of clips 36 and screws 38. Balance weights 40 are provided for poising the wheel. A roller table 42 is carried by the balance staff 24 and has an insulated contact 44 and pin 46 mounted thereon. The contact 44 is connected to one terminal of the coil 34. The movement is provided with a watch face 82 and with hour, minute and second hands 84, 86 and 88.

A plate 48 secured to the pillar plate of the watch carries a first post 50 and a second post 52. Each of these posts has respectively mounted thereon collets 54 and 56, and both posts and collets are insulated from the plate 48 in a manner described in further detail in assignees copending application, Serial No. 551,791, filed December 8, 1955. A controlling spring arm 58 is carried by collet 54 and a second spring arm 60 is carried by collet 56. The second spring arm 60 carries at its end a contact which is adapted to engage the contact. 44 on roller table 42. The first spring arm 58 serves as. member and is engageable by- 42. Spring arms 58 and 60,. contact 44 serve as a contact; periodically connecting the coil: manner described in detail in ascopending application Serial No.

the pin 46 on roller table roller table 42, pin 46 and making arrangement for 34 to the battery 14 in a signees aforementioned 551,791.

1 Disposed about the periphery of pillar plate 12 is a circular type magnet 62 of rectangular cross-section having oppositely polarized ends 64 and 66 adjacent the balance wheel 28. A pair of generally L-shaped pole pieces 68 and 70 have first legs 71 and 73 which engage the ends 64 and 66 of magnet 62, and second legs 75 and 77 which engage the inner surfaces of the ends of the circular magnet. These pole pieces are provided with plate-like portions 72 and 74 extending therefrom. The plate-like portion 72 extends from the upper end of pole pieces 68, as seen in Figure 2, while plate-like portion 74 extends from the lower end of pole piece 70, as seen in the same figure. The plate-like portions 72 and 74 extend toward one another and also toward the center of the watch movement. The two portions overlap at their inner ends and are provided with thickened pole portion 76 and 78 at this position of overlap. As Will be understood by those skilled in the art the thickened portions 76 and 78 overlie one another to establish therebetween a magnetic field which is magnetically axial in direction but which extends substantially radially with respect tothe watch movement. As can be seen in Figure 1, the contact system is arranged so as to supply current tothe coil 34 when one leg 80 thereof is disposed i the magnetic field between thickened pole portioiis 76 and 78.

"In the o eration of th watch, eurrent fiowing from the battery 14 energizes "the coil only at the moment it is in 'the' magnetic field between thickened pole portions '76 and '78. this energization of the coil produces a magnetic thrust'which is transmitted to the balance wheel and, in cooperation-with the reaction of the hair-spring, produces oscillatihg niotioh. The oscillation of the balance wheel moves the roller table and its jewel pin and the contact 44 to provide the proper s'witching'as is described in detail in the aforementioned copending application Serial No. 551,79.

The pillar plate 12 is formed of a suitably non-magnetic material, such as' brass or nickel-silver,- while the pole pieces are formed of magnetic material such as lowca'rbon steel. Because of the high length to diameter ratio which thisshape magnet makes possible it is feasible to use magnetic materials such as Alnico V magnets. While the battery is shown as being mounted within the watch case, it willbe appreciated that the battery could also'be mounted outside of the case as a decorative feature of the Watch band. 7 1

While the watch shown in Figures 1 and 2 utilizes a magnetic circuit which produces but a single intensified magnetic region cutting only one leg of the. coil, it ,is also contemplated that a pair of intensified magnetic regions u 213' be produced to provide impulses in both legs'of the coil simultaneously. Referring to Figures 3 and 4 there is shown an embodiment of a watch having this type of magnetic circuit arrangement.

'Re'fe'rring to these figures, there is seen a watch 9i) comprising a pillar plate 92 on which is mounted a battery'94. The battery 94 is mounted by means of a spring 93 as in the preceding embodiment of the invention. A balance staif 113i) is mounted in suitable bearings in the pillar plate 92 and balance cock 102 and a conventional hair spring 104 is provided. A balance wheel1tl6 having a rim 108 is mounted on the balance staff by means of support arms 110 connected to a suitable hub. A watch face 112 and hands 114, 116 and 118 are also provide Contact spring arms 120 and 122 are mounted on collet and post assemblies 124 and 126 upon a plate 128, as in the preceding embodiment of the invention. A roller table 131} is mounted on balance staif 109 and carries pin 132 and contact 134. These cooperate with the spring arms 121) and 122 as in the preceding embodimerit of the invention. The balance wheel carries a sectorshaped coil 136, which may be mounted thereon by means of clips 138. v c j I Disposed about the movement of watch 90 is a circular magnet 140 having oppositely polarized ends 142 and 144. Disposed in contact with ends 142 and 144 are a pair of pole pieces 146 and 148 which are generally L-shaped and have first arms 149 and 151 engaging the ends o f the magnet and second arms 153 and 155 engaging the inner faces of the magnet. Inwardly extending arms 150 and 152 are attached to the lower ends of the pole pieces, as seen in Figure 4. The arms 150 and 152 extend inwardly towards the center of the watch 164 and 166'and non-magnetic sleeves 168 and 170. The screw-s 164 and 166 engage screw-threaded holes in the pillar plate 92 and the height of the sleeves 168 and 170 is such that the shunt 16 2 is mounted above the coil 136 in close proximity thereto, as is seen in Figure 4.

The thickened pole portions 154 and 156 are so disposed with relation to the coil 136 that one pole portion lies under one leg of the coil while the other pole portion simultaneously lies under the other leg of the coil. It will be apparent to those skilled in the art that a pair of intense magnetic regions are produced between pole piece 154 and shunt 162 and between pole piece 156 and shunt 162, the shunt completing the magnetic circuit between the two ends of the magnet 140. With this arrangement both legs of the coil 136 simultaneously receive magnetic impulses from the magnetic field so that for a given current in the coil, a larger total impulse is produced than withthe embodiment of the invention shown in Figures 1 and .2. c c

The operation of this embodiment of the invention is similar to that shown in Figures 1 and 2. Current flowing from battery 94 energizes the coil at the moment that its legs are: in the magnetic fields between the thickened pole portions and the shunt and this produces a pair of magnetic thrusts against the coil. The total thrust is transmitted to the balance wheel which cooperates with the hair spring to produce oscillating motion. The contact arrangement energizes the coil to produce impulses of this type every time the balance wheel moves to the position shown in Figure 3, in the same manner as described in connection withthe preceding embodimentof the invention and as described in more detail in assignees aforementioned application, Serial No; 551,791.

' The pillar plate is again preferably formed of a nonmagnetic material such as brass or nickel-silver while the pole pieces and shunt are formedof soft-magnetic material such as low-carbon steel. The magnet again possesses a high length to diameter ratio.

The invention may be embodied in other specific forms without departing from'the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims aretherefore intended to be embraced therein.

What is claimed and desired to be secured by the United States Letters Patent is: l

1. An electric time piece comprising, ;a balance stall and balance assembly, a coil carried by said balance staff, a circular magnet encircling said balance staff and balance assembly and having ends disposed adjacentsa'id coil, and pole piece means engaging said ends and arranged to produce at least one intensifiedmagnetic region through which said coil moves. V, a 2. An electric time piece comprising, a balance staff and balance assembly, acoil carried by said balance staif and generally lying in a plane perpendicular thereto, a circular magnetic eccentrically encircling said balance 7 staff and balance assemblyand having ends disposed admovement and terminate in thickened pole portions 154 and 1.56.

jacent saidcoil, and pole piece means engaging said ends and arrangedto produce at least one intensifiedmagnetic region having a magnetic substantially parallel to said balance staff, said coil being mounted for movement through said intensified magnetic region.

3. An electric time piece comprising, a balancestaff and balance assembly, a coil carried by said balance stall and generally lying in .a plane perpendicular thereto, a circular magnet eccentrically encircling said balance staif and balanceassembly and having :ends disposed adjacent saidjcoil, said ends being no more than apart with reference to the center 'of said time piece, pole piece means associated With-thecnds, of .said magnet, said pole piece means including afirst ppole piece engagingone end of said magnet and having a portion extending toward the center of said time piece, and a second pole piece engaging the other end of said magnet and having a portion extending toward the center of said time pieec to produce at least one intensified magnetic region having a magnetic axis substantially parallel to said balance stafi through which said coil is mounted for movement.

4. A time piece as set out in claim 3 wherein said intensified magnetic region is within the circle defined by said magnet.

5. A time piece as set out in claim 4 wherein said magnet encircles said time piece.

6. A time piece as set out in claim 3 wherein said pole pieces extend toward one another and have overlying portions producing an intense magnetic region therebetween.

7. A time piece as set out in claim 6 wherein said first pole piece has a portion extending toward the center of said time piece from the top thereof, and said second pole piece has a portion extending toward the center of said time piece from the bottom thereof, said extending portion of said first pole piece partially overlying said extending portion of said second pole piece to produce an intense magnetic region therebetween.

8. A time piece as set out in claim 7 wherein said extending portions of said pole pieces are thickened at said overlying area.

9. A time piece as set out in claim 3 wherein said pole piece means includes a shunt overlying but spaced from said extending portions of said pole pieces to form two intense magnetic reg ons between said shunt and said extending portions of said pole pieces.

10. A time piece as set out in claim 9 wherein said extending portions extend from the same ends of said pole pieces and are thickened adjacent said shunt.

References Cited in the file of this patent UNITED STATES PATENTS 1,964,857 Neumann July 3, 193-4 FOREIGN PATENTS 578,457 Germany June 14, 1933 764,450 Great Britain Dec. 28, 1956 923,788 France Feb. 24, 1947 

